Railroad track alignment method and apparatus

ABSTRACT

A method and apparatus for the alignment of a railroad track wherein there is carried out a leveling operation and a slewing operation which is incorporated in the tamping cycles for the tamping of the ballast. Upon completion of a tamping cycle the leveling operation is terminated, but the lateral track position is fixedly maintained for a predetermined period of time after completion of such leveling operation.

I United States Patent [1113,568,604

[72] Inventor Gerard Sauterel [56] References Cited Pullhswitwhnd UNITED STATES PATENTS P 3,134,339 5/1964 Plasseretal. 104/8 [221 PM 1968 3 381 626 5/1968 Fa gan et a1. 104/7 meme! 3 401 642 11/1966 Fisher 104/7 [73] Assignee MATISA M t i m 1 Crissier pres Lausanne, Switzerland Primary Examiner-Arthur L. La Point [32] Priority Jan. 20, 1967 Assistant Examiner-Richard A. Bertsch [33] Switzerland Atrorney- Werner W. Kleeman [31] 885/67 [54] ALIGNMENT METHOD AND ABSTRACT: A method and apparatus for the alignment of a 7 Claims, 5 Drama Figs railroad track wherein there is carried out a leveling operation a and a slewing operation which is incorporated in the tamping [52] US. Cl 104/8 cycles for the tamping of the ballast. Upon completion of a [51] lnt.Cl E01b 33/02, tamping cycle the leveling operation is terminated, but the E01!) 35/08 lateral track position is fixedly maintained for a predeter- [50] Field of Search 104/6, 7, 8, mined; period of time after completion of such leveling opera- 78 tion.

IOI

Patented March 9, 1971 3 Sheets-Sheet 1 ATTOE/VEYS Patented March 9, 19 71 3 Sheets-Sheet 2 //VI/EN70f 6564/20 52075? 7;

RAMOADTRACK ALIGNMENT METHOD AND APPARATUS BACKGROUND OF THE INVENTION The present invention relates to an improved method for the mechanized alignment of the direction of the line of a railroad track, and furthermore, pertains to an improved ap paratus for the performance of the aforementioned inventive method.

The alignment of the direction of the line of a railroad track normally follows the construction or the renewal of a railroad track. This operation encompasses the exact adjustment of the track position in plan as well as the adjustment of the elevationallposition of each track rail or string. Both of these partial operations, which normally are referred to as lining and level ing, are usually carried out separate from one another with the aid of manual tools or by means of machines.

The present invention contemplates an increased mechanization in which the leveling and lining operations are undertaken within uniformly occuring tamping cycles. These tamping cycles oftentimes expire without the intervention of a human being owing to the automatic controls which are characteristic of modern track laying machines. This likewise requires an automatic regulation of the leveling and lining operations, based upon the scanning or detection of the position of the track rails.

One type of machine which is used quite often by railroad networks is equipped with rail clamps or hooks, the construction of which can vary. However, all of these rail clamps or hooks engage the track rails during standstill of the machine, lift them and hold them at a predetermined height, during which time the tamping tools which are mounted on the same machine compact the ballast beneath the crosstie or sleeper which is situated closest to the lifting location. The lining operation occurs at the same time as the leveling operation. The purpose of the tamping operation is to fix the track position by anchoring each individual crosstie in the ballast.

' However, after the rail clamps or hooks are opened the portion of the track which is held in suspension in front of the last anchored crosstie falls back onto the ground owing to its own weight. When the machine has moved through a path of displacement to the next crosstie, then the rail clamps are again closed about the rail heads and a new tamping cycle is started into operation.

it was then oftentimes determined that the direction of the line of the track in plan exhibited irregularities behind the machine. Such primarily occur in curves. The most plausible explanation for this occurrencewhich by the way appears to have been substantiated by the results obtained by means of the present inventionis that the track is laterally displaced by the components of the forces which act upon the track rails and which are directed transverse to the axis of the railroad track.

With regard to these forces, and in the case of a curve, there must be primarily mentioned the component of the inherent weight of the track which is directed parallel to the inclination of the track plane. To this load there also must be considered the internal stress in each of both track strings or rails which results in the track rails tending to straighten themselves.

in straight stretches of track the prestresses which appear in the rails, and which are brought about by thermal or mechanical treatment of the rail material during laying of the track or during welding at the track, cause displacements when the track is raised from the ballast bed.

SUMMARY OF THE lNVENTlON Accordingly, it is a primary object of the present invention to provide an improved method of, and apparatus for, the mechanized alignment of the direction of the line of a railroad track, which effectively overcomes the aforementioned drawbacks of the prior art structures.

Still a further significant object of this invention relates to an improved method of, and apparatus for, effectively and reliably aligning a railroad track in an extremely simple, precise and efficient manner.

Now, the inventive method for the mechanized alignment of the direction of the line of a railroad track, which is the objective of the present invention and which embodies leveling and lining operations, whereby these partial operations are incorporated or integrated in the tamping cycles, wherein the leveling operation always terminates at the end of a cycle, provides a simple means for overcoming the aforementioned drawbacks. According .to an, important aspect of the inventive method the lateral track position is fixedly retained after termination of the leveling operation.

One specific embodiment of the inventive method resides in fixedly retaining the lateral track position during a predetermined time interval after cessation or termination of a leveling operation, and wherein the aforementioned time interval at least corresponds to the period of time required for the return or repositioning of the track after stopping of the leveling operation.

The inventive apparatus for carrying out the previously considered method of the present invention incorporates means for regulating the leveling operation and means for regulating or controlling the lining or slewing operation. More precisely, the inventive apparatus is characterized by the features that it employs a control means having a time-delayed action wherein the time-delay interval begins with the termination of a leveling operation and at the terminal phase or end of the aforementioned time-delay interval the control means brings about the release of the lateral track position by the slewing means.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will be better understood, and objects other than those set forth above will become apparent, when consideration is given to the following detailed description thereof. Such description makes reference to the annexed drawings, wherein like reference numerals have generally been employed for similar or analogous elements throughout,

DESCRIPTION OF THE PREFERRED EMBODIMENTS Describing now the drawings, and with reference initially made to FIGS. 1 and 2, it is to be recognized that the track T which is to be aligned is represented by both of the track rails or strings I and 2. The inventive apparatus, which will be discussed in detail hereinafter, is mounted upon a mobile track vehicle 3 which is capable of moving along the railroad track T. ln FIG. 1 only the forward axle i of this track vehicle 3 has been shown in order to simplify the drawing and particularly since the remainder of such vehicle is not necessary to the understanding of the invention.

The groups of conventional tamping tools 5 are arranged at a foreslung or overhanging portion lliiil of the chassis or frame 1M of the track vehicle 3. These tamping tools 5 are mounted so as to be vertically displaceable in the usual manner at tamping units or casings h which can be raised and lowered by means of hydraulic jacks or cylinder units 7 of standard construction.

At the front of the frame or chassis Till of the track vehicle 3 there is mounted an apparatus for slewing or lining the track.

This slewing or lining apparatus may be of the type shown and described in the commonly assigned, copending Canadian patent application, Ser. No. 997,754, filed Aug. 14, 1967. In the illustrated exemplary embodiment this slewing apparatus essentially incorporates two slewing arms 9 equipped with lateral pressure rollers 9a and a fluid actuated, e.g., hydraulic slewing cylinder 10. As will be seen by inspecting FIG. 3, a piston member 102 is slidably arranged within the slewing cylinder 10. Furthermore, it will be recognized that the slewing arms 9 are pivotably mounted at a respective pivot shaft 11 and 12 at the frame 101 of the track vehicle 3. The longitudinal axis of the cylinder unit 10 crosses the connecting line between the pivot shafts 11 and 12. It should be understood that a shortening of the cylinder unit 10 brings about a pivoting of the arms 9 in clockwise direction so that the track T is displaced in the direction of the arrow A appearing in FIG. 2. An extension of the cylinder unit 10, on the other hand, results in the track T being displaced in the direction of the arrow B, also shown in FIG. 2.

Continuing, it will be recognized that a suitable leveling apparatus is located between the groups of tamping tools and the aforedescn'bed apparatus for slewing the track. This leveling apparatus has been schematically depicted at the bottom of FIG. 4, by way of example, yet it should be expressly understood that such has only been shown in the drawings as an exemplary embodiment of leveling mechanism, since other suitable leveling devices could be employed without departing from the teachings of the present invention.

Now, considering this leveling apparatus in greater detail, it should be understood that the central portion thereof is formed by a frame member consisting of a rigid plate 13. This plate 13 is connected in such a manner with the frame 101 of the track vehicle 3 that the plate 13 can freely move in a transverse plane with respect to the axis of the railroad track T. For this purpose, the plate member 13 is suspended by means of rods 14 at the slide members 15, the latter of which are guided in suitable guide rails 16 which are rigidly connected with the frame of the track vehicle 3.

Furthermore, it will be understood that fluid actuated, for instance hydraulic track lifting jacks or cylinder units 17 and 18 are secured to the opposite vertical lateral edges of the plate member 13, as best shown in FIG. 4. The respective piston rods 103 and 104 of each of these cylinder units 17 and 18 is downwardly extended and carries a respective support plate or foot member 19 which bears against the ballast at both sides of the railroad track T. Plate member 13 can be fixedly connected with the railroad track T through the agency of a rail clamp unit 105. The latter incorporates two rail books or clamps 20 which can be applied to both of the track rails or strings I and 2 by means of a fluid actuated, e.g., hydraulic cylinder unit 21.

This arrangement of the leveling mechanism or apparatus is undertaken in such a manner that it is possible to individually raise each track rail 1 or 2 by means of the cylinder units 17 and 18, respectively.

There will now be considered the hydraulic and electric circuits appearing, by way of example, in FIGS. 3 to 5. It is here mentioned that in these schematic circuit diagrams there have only been incorporated the details of those components which are significant for a complete understanding of the teachings of the present invention. Therefore, in order to simplify the illustration certain elements have been omitted which are not completely necessary for understanding the inventive method and apparatus, but the addition of which would be apparent to the person skilled in the hydraulics art. Furthermore, some of the elements depicted in these FIGS. have been schematically represented in order to simplify the illustration, and particularly since the specific details thereof are well known to those skilled in the art and do not constitute part of the inventive subject matter.

With the foregoing understanding, and turning attention now to the hydraulic circuit diagram of FIG. 3, which is concerned with the control or regulation of the slewing or lining operation, it will be seen that the infeed of pressurized medium to the slewing cylinder 10 takes place by means of two series connected hydraulic distributor valves 25 and 27, which are of known construction. The first distributor valve 25 has two operating positions and its schematically represented valve body or slide 25a is actuated by means of a suitable electromagnet 26 or equivalent structure. In the illustrated rest position of the distributor valve 25 the connecting conduits or lines 106, 107 to both of the pressure chambers 10a and 10b of the cylinder unit 10 are operably coupled with one another at the distributor valve unit 25. As a result, the pressurized medium does not provide any resistance against movement of the piston 102 within the cylinder 10. Thus, both of the slewing arms 9 passively follow the direction of the line of both track rails 1 and 2 during the forward advancement or movement of the track vehicle 3.

Now, when the electromagnet 26 is furnished with current then the cylinder unit 10 is controlled by the two-stage hydraulic distributor valve unit 27. As will be explained in greater detail hereinafter, in the first stage of this distributor valve unit 27 the electric signal which is delivered by a suitable known position detector or feeler for the track, is transformed into a hydraulic control pressure which serves to move the control piston 108 of the second stage. This control piston 108, as shown in FIG. 3, is subjected to the counteraction of two return springs 109 and 110 or equivalent structure, and by means of which this control piston 108 is retained in its neutral or central position in which both connections of the distributor valve 27 leading to the cylinder 10 are closed. The transformation of an electrical signal into a hydraulic signal is achieved through the agency of an electromagnet 28 which is mounted at the first stage of the distributor valve unit 27. These signals are continually variable and can change their polarity in accordance with the scanned position feeler or detector.

The hydraulic working medium which is delivered by a suitable pump unit 30 is conducted from the distributor valve unit 27 through the agency of the distributor valve unit 25 to one or the other pressure chamber or 10b of the cylinder unit 10, depending upon the polarity of the control current at the electromagnet 28. During such time as the pressurized medium is delivered to one or the other of the pressure chambers 10a or 10b the other pressure chamber of the cylinder 10 is operably coupled with an open pressure medium reservoir or container 111. The amount or quantity of pressurized medium is continuously regulated by the distribt tor valve unit 27 as a function of the control current at the electromagnet 28. A suitable pressure limiting device 31 insures for a constant pressure at the pressure side of the pump unit 30 while conducting away the surplus quantity of pressurized medium to the reservoir or tank 111.

The control of the different electromag'nets, not only those shown in FIG. 3 but also those which will now be described in connection with FIG. 4, will be explained during the discussion of the electric circuit diagram of FIG. 5. However, before undertaking such, reference is now made to the hydraulic circuit diagram of FIG. 4.

The hydraulic circuit of this FIG. serves to control the leveling operation. To this end, the closing and opening of the rail clamps or hooks 20 of the rail clamp unit is controlled by a hydraulic distributor valve 32, similar to the valve unit 25 of FIG. 3, and having two operating or switch positions. This distributor valve 32 is actuated by means of the associated electromagnet 33. In the rest condition of electromagnet 33 the pressurized medium is conducted into the pressure chamber 21a at the piston rod side of the cylinder unit 21, whereas the pressure chamber 21b at the free side of the piston 11?. communicates with the reservoir or tank 113. Here again, a suitable pressure limiting device 114 cooperates with the sociated pump unit 115. in the illustrated position of the distributor valve 32 the rail clamps or books 20 are raised away from the rails 1 and 2, as shown. In order to apply these rail hooks against the rails 1 and 2, it is necessary to excite the electromamiet 33, so that the pump H5 communicates with the pressure chamber 2% of the cylinder unit 21 at the free side oi the piston M2 and the reservoir H3 communicates with the other pressure chamber 21a.

By further referring to H6. 4 it will be seen that the track lifting cylinder E7 is operably connected with a distributor valve unit 34 having two operating or switching positions and incorporating an electromagnetic actuation, as represented by the electromagnet 35. Now, when this electromagnet 35 is without current, then the flow of pressurized medium emanating from the pump unit lid is to the lower pressure chamber l7a of the lifting cylinder unit 17 and by means of the conduit lll, whereas the upper chamber 17b communicates with a suitable fluid reservoir or tank lid byv means of the conduit 119. The piston member 120 of the cylinder unit 17 is then completely retracted within its cylinder compartment and the associated foot plate 19 is raised from the ground.

Now, when the electromagnet 35 is energized, then the four outlet openings of the distributor valve 3 are closed, so that the control of the cylinder unit 117 takes placeby means of a two-stage hydraulic distributor valve unit an. The latter is constructed in a manner similar to the distributor valve unit 27 of FIG. 3 and is likewise retained in its central or neutral position by two oppositely acting return springs 12]; and 122 or equivalent structure. The first stage of this distributor valve unit as serves for transforming the electric signal delivered by the position detector or feeler of the track rail or string 1 into a hydraulic control pressure which is employed for actuating the piston member 1123 of the second stage of this distributor valve unit as. The transformation of the electrical signal into an hydraulic control pressure is undertaken by means of an electromagnet 37 mounted at the first stage of this distributor valve unit as. Depending upon the polarity of the electrical signal the pressurized medium is either conveyed into the upper compartment or chamber 171; or into the lower chamber li'a of the cylinder unit 17. The aforedescribed arrangement therefore serves for regulating the elevational position of the track rail or string 11. Finally, it is mentioned that a suitable pressure limiting device H24 is operably associated with the pump unit lilo.

Furthermore, it should be understood that the control elements for the other track lifting cylinder unit lb are constructed in an analogous manner. Once again, it will be recognized that the cylinder unit 18 incorporating therein a sliding piston member 12% which subdivides the cylinder 18 into the pressure chambers Mia and 1812, respectively, is connected on the one hand with the distributor valve unit 411 having two operating or switching positions and associated with the electromagnet $23. On the other hand, this cylinder unit lb is connected with the two-stage distributor valve unit 43 which is held in its central or neutral position by the return springs 126 and K27. 'lhisdistributor valve unit $3 is operably associated with the electromagnet i l for producing the precontrol pressure, and similar to the electromagnet 37 previously considered in connection with the cylinder unit 17. Since the operation of the components associated with the cylinder unit 1% is completely similar to the operation of the cylinder unit l7, no further discussion would appear to be necessary. Furthermore, the remaining components of the hydraulic circuit associated with cylinder unit iii have applied thereto the same reference numerals as were used for the analogous components considered in connection with the hydraulic cylinder unit 117, but further incorporate a prime marking next to each such reference numeral. Thus, for instance, it will be seen that the pump unit associated with the cylinder 11% has been designated by reference numeral llti'.

As will be recalled, the electric circuit diagram depicted in FlG. 5 has been considerably simplified in order to improve its comprehensibility. The electromagnets 2s, 33, 35 and 42 are of the "on-off" type and are controlled by the interrupter contact 45. This interrupter contact 45 is actuated either manually or by means of a foot lever and remains closed as long as it is not opened. Opening of the electric contact 45 can either occur manually or mechanically through the movement of a movable element during the course of a tamping cycle. However, the electromagnet 26 is subjected to the action of the time-delay relay means as having a delayed deenergization time. The time-delay relay means do closes its associated contact as directly after it is excited, yet only opens such contact 36 after a predeterminedperiod of time after opening of the interrupter contact 45. in this time interval the rail clamps or hooks 2b are released owing to the absence of current at the associated electromagnet 33 and the track falls back onto the ballast bed owing to its own or inherent weight. Practical experience has shown that an interval of approximately 1 second is sufficient. It is important that the track returns or is repositioned without any change in the transverse position of the railroad track. This is the reason why the timing relay as still maintains for a few moments the control of the slewing operation by the distributor valve unit 27.

By further referring to ,the electric circuit diagram of FlG. 5 it will be recognized that amplifier means 47 are provided in order to amplify the electrical signals delivered by the associated measuring transducer means. These measuring transducer means, which have been conveniently omitted from the drawing, are mounted at the position feelers or detectors for the track position. These track positioning feelers have only been schematically represented in FIG. 5 by the reference numerals 130, 1131 and 132. Thus, it will be further recognized that FIG. 5 also shows the electrical conductors 438, 69 and 50 which lead to the position feelers or detectors 1130, 131 and 132, respectively. More precisely, the conductor 49 is electrically coupled with the position feeler 330 for the lateral track position, the conductor or lead 49 is electrically coupled with the position feeler 131 for the elevational position of the track rail 2, and the remaining conductor 50 is electrically coupled with the corresponding feeler or detector for the elevational position for the track rail 1. In the described embodiment, these signals have continuously variable algebraic values. They are transformed in the first stages of the distributor valves 27, 36 and 43 into hydraulic control pressure signals which are capable of displacing the associated control piston of the second stage of the associated distributor valve unit in both opposed directions out of the neutral or central position.

ln the described embodiment, which has been given purely by way of example and not limitation, the electromagnets 37 and M are dependent upon the operation of the relay M which is actuated by the previously mentioned interrupter contact 455. This arrangement ensures that the connections of the distributor valve units as and 43 to the cylinders l7 and i8, respectively, are closed, when the contact 45 is open. According to a variant embodiment of the invention, the electromagnet 28 can be likewise made dependent upon the operation of the relay M, and this has the consequence that the distributor valve unit 27 remains in the central position, and therefore the cylinder unit ll) remains locked until the distributor valve unit 25 has returned into its rest position owing to deenergization of the associated electromagnet 26. ln this manner the track is prevented from laterally sliding away during such time as it drops back onto the bed of ballast.

Finally, it is still to be mentioned when considering the possible variant embodiments of the invention that instead of the electromagnetically controlled distributor valve units 25, 34 and 411 it would be possible to employ suitable pressure controlled distributor valve units. Moreover, the integration of the slewing and leveling operations in the automatic tamping cycles can result in a person skilled in the hydraulic control art constructing modified circuits without departing from the spirit and scope of the underlying concepts of the present invention.

Furthermore, it should be understood that the release of the slewing forces can also be delayed in time by other time-dependent devices than the illustrated electromagnetic timedelay relay means, for instance by means of hydraulic time delay elements or equivalent devices. Furthermore, the term hydraulic" as employed herein is used in a broader sense to encompass fiuid responsive or fluid operated elements and is not to be construed as limited solely to liquid actuated, for instance hydraulic units which are operated by oil or another appropriate pressurized liquid medium.

Thus, while there is shown and described present preferred embodiments of the invention, it is to be understood that the invention is not limited thereto, but may be otherwise variousiy embodied and practiced within the scope of the following claims.

I claim:

1. A method for the mechanized alignment of the direction of the line of a railroad track, including the steps of leveling and slewing the track whereby the track is slewed as the track is maintained above the ground by the leveling operation, the partial operations of track leveling and slewing being incorporated in the tamping cycles for the tamping of the ballast of the railroad track, stopping the leveling operation each time at the termination of a tamping cycle, and fixedly retaining the lateral position of the railroad track after completion of the leveling operation during a predetermined time interval after termination of the leveling operation, such predetermined time interval at least corresponding to the period of time necessary for the repositioning of the railroad track after completion of the leveling operation.

2. A method for the mechanized alignment of the direction of the line of a railroad track, as defined in claim 1, wherein said predetermined time interval is approximately 1 second.

3. An apparatus for the mechanized alignment of a railroad track comprising means for carrying out a leveling operation, means for controlling said leveling operation, means for carrying out a slewing operation, means for controlling said slewing operation, and control means operating with a time delay, wherein the interval of said time delay begins upon termination of said leveling operation when the track is being repositioned and, in the terminal phase of said time-delay interval, said control means brings about the release of the lateral track position by said means for carrying out a slewing operation.

4. An apparatus for the mechanized alignment of a railroad track comprising means for carrying out a leveling operation, means for controlling said leveling operation, means for carrying out a slewing operation, means for controlling said slewing operation, and control means operating with a time delay, wherein the interval of said time delay begins upon termination or" said leveling operation and, in the terminal phase of said time-delay interval, said control means brings about the release of the lateral track position by said means for carrying out a slewing operation, further including an electrical control circuit operably coupled with said control means, means for interrupting said electrical control circuit, said control means operating with a time delay comprising electromagnetic relay means possessing a time-delayed deenergization period, said electromagnetic relay means being dependent upon said electrical control circuit, the interruption of which bring about termination of said leveling operation and the time-delayed deenergization of said electromagnetic relay means.

5. An apparatus for the mechanized alignment of a railroad track as defined in claim 4, wherein said electrical control means further includes amplifier means.

6. An apparatus for the mechanized alignment of a railroad track as defined in claim 5, wherein said interrupting means embodies an interrupter contact. 4

7. An apparatus for the mechanized alignment of a railroad track as defined in claim 6, further including relay means operable by said interrupter contact for controlling said amplifier means. 

1. A method for the mechanized alignment of the direction of the line of a railroad track, including the steps of leveling and slewing the track whereby the track is slewed as the track is maintained above the ground by the leveling operation, the partial operations of track leveling and slewing being incorporated in the tamping cycles for the tamping of the ballast of the railroad track, stopping the leveling operation each time at the termination of a tamping cycle, and fixedly retaining the lateral position of the railroad track after completion of the leveling operation during a predetermined time interval after termination of the leveling operation, such predetermined time interval at least corresponding to the period of time necessary for the repositioning of the railroad track after completion of the leveling operation.
 2. A method for the mechanized alignment of the direction of the line of a railroad track, as defined in claim 1, wherein said predetermined time interval is approximately 1 second.
 3. An apparatus for the mechanized alignment of a railroad track comprising means for carrying out a leveling operation, means for controlling said leveling operation, means for carrying out a slewing operation, means for controlling said slewing operation, and control means operating with a time dElay, wherein the interval of said time delay begins upon termination of said leveling operation when the track is being repositioned and, in the terminal phase of said time-delay interval, said control means brings about the release of the lateral track position by said means for carrying out a slewing operation.
 4. An apparatus for the mechanized alignment of a railroad track comprising means for carrying out a leveling operation, means for controlling said leveling operation, means for carrying out a slewing operation, means for controlling said slewing operation, and control means operating with a time delay, wherein the interval of said time delay begins upon termination of said leveling operation and, in the terminal phase of said time-delay interval, said control means brings about the release of the lateral track position by said means for carrying out a slewing operation, further including an electrical control circuit operably coupled with said control means, means for interrupting said electrical control circuit, said control means operating with a time delay comprising electromagnetic relay means possessing a time-delayed deenergization period, said electromagnetic relay means being dependent upon said electrical control circuit, the interruption of which bring about termination of said leveling operation and the time-delayed deenergization of said electromagnetic relay means.
 5. An apparatus for the mechanized alignment of a railroad track as defined in claim 4, wherein said electrical control means further includes amplifier means.
 6. An apparatus for the mechanized alignment of a railroad track as defined in claim 5, wherein said interrupting means embodies an interrupter contact.
 7. An apparatus for the mechanized alignment of a railroad track as defined in claim 6, further including relay means operable by said interrupter contact for controlling said amplifier means. 